Finding the Fourth Proportional to 20,958.96, 31,428.72 and 12,196.38

Step by Step Solution

1. Step 1: Write the proportion equation
   20,958.96 : 31,428.72 = 12,196.38 : x
2. Step 2: Convert to fraction form
   20,958.96/31,428.72 = 12,196.38/x
3. Step 3: Cross multiply
   20,958.96x = 31,428.72 × 12,196.38
4. Step 4: Simplify right side
   20,958.96x = 383,316,612.03
5. Step 5: Solve for x
   x = 383,316,612.03/20,958.96
6. Step 6: Final answer
   x = 18,288.91